Nutritivni doprinos šumskog voća u borbi protiv oksidacijskog stresa

master's thesis

• Title (english): Nutritional contribution of berries while fighting oxidative stress
• Author: Ivana Bečić
• Mentor: Jasenka Gajdoš Kljusurić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Measurement, Regulation and Automatisation); Zagreb
• Defense date and country: 2013-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Stres je prisutan u svakom organizmu, stoga je nužna ravnoteža između proizvodnje slobodnih radikala i unosa antioksidanasa. Organizam najbolje iskorištava nutrijente iz prirodnih izvora tj. hrane, a slabije iz dodataka prehrani. Šumsko voće nudi bogatstvo vitamina, mineralnih tvari i fitokemikalija od kojih većina imaju antioksidacijska svojstva. Cilj je rada bio ispitati udio ukupnih fenola (UF) i Briggs-Rauscherovom metodom odrediti antioksidacijsku aktivnost (AOA) šumskog voća (jagode, kupine, maline, borovnice i crveni ribizl) te dodatka prehrani vitamina C. Prilikom ekstrakcije fenolnih spojeva primijenjene su dvije metode: refluksiranje i ekstrakcija u ultrazvučnoj kupelji. Također se provela kolorimetrijska analiza uzoraka. Rezultati ukazuju na najveću koncentraciju UF u uzorku dodatka prehrani vitamina C, ali i najmanju AOA istog uzorka. Korišteni su jednostavni regresijski modeli kako bi se ustanovilo postoji li linearna povezanost ispitivanih parametara. Prema navedenom modelu, koncentracija UF šumskog voća je u pozitivno linearnoj vezi s AOA izraženoj kao BriggsRaucherov antioksidacijski indeks. Kolorimetrijska analiza pokazala je da tamniji i više plavo-zeleni ekstrakti imaju jaču AOA od onih svjetlijih i žuto-crvenih. Rezultati t-testa i ANOVA pokazuju da ne postoje signifikantne razlike između uzoraka dobivenih različitom metodom ekstrakcije (p > 0,05).

Abstract (english)

The balance between the production of free radicals and antioxidant intake is very important because of the stress that is present in every organism. Human body utilizes better the nutrients from natural sources, i.e. food, then from supplements. Wild berries offer a range of vitamins, minerals and phytochemicals, and the most of them have antioxidant properties. The aim of this work was to examine the berries (strawberries, blackberries, raspberries, blueberries and red currants) and supplements of vitamin C, by determining the share of total phenols (TP) and the antioxidant activity (AOA) using the Briggs-Rauscher's method. In the extraction were used two methods: with reflux and using ultrasound. Also was conducted a colorimetric analysis of the samples. The results indicate the highest concentration of TP in the vitamin C (supplement sample) that had also the smallest AOA. Simple regression models were used to identify if some correlation between the measured variables can be detected. According to such model, the concentration of TP in berries is positively correlated with the AOA expressed as Briggs-Rausher antioxidant activity index. Colorimetric analysis showed that the darker and extracts with domination of blue-green color have more antioxidant power than the lighter and yellow-red samples. The results of t-test and ANOVA showed no significant differences between the sample extraction (p > 0,05).

• Keywords: stres; šumsko voće; fenolni spojevi; antioksidacijska aktivnost; kolorimetrija
• Keywords (english): stress; berries; phenolic compounds; antioxidant activity; colorimetry
• Language: croatian
• URN:NBN: urn:nbn:hr:159:308849
• Study programme: Title: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra nutricionizma (magistar/magistra nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-05 11:59:01